What is Vidar / Arkei malware?
Vidar is an information stealer Trojan that was first identified in December 2018. It is either a fork of Arkei or the result of its evolution. Named after the god of vengeance from Scandinavian mythology, Vidar is used to steal information from infected machines, take screenshots, steal cryptocurrency and more.
General description of Vidar
Vidar is presumed to have originated in a Russian speaking country since the malware is configured to stop execution if it detects that it is being run on a machine that is located in one of the ex-USSR nations or on one that has a Russian keyboard layout.
Being another malware that is available for purchase based on the MaaS ( Malware-as-a-Service ) business model, Vidar can be purchased on its “official” website for a hefty price tag of $700, at least for the PRO version. Though, a stripped-down version of the malware can be obtained for just $250.
Vidar is written in C++ programming language. Purchasing account grants the attacker access to a control panel where the malware can be set up by the cybercriminal to target particular information on the victims’ PC. Similarly to Arkei, Cybercriminals need to take precautions to secure the main payload themselves, using a cryptor or a packer. The control panel displays the current builder version, user settings, malware status, and logs. It should be noted that domain names which Vidar uses to search for C&C servers, where stolen data is being dropped to, change every four days.
Vidar is capable of stealing text files in multiple formats, browser cookies and history, browser records, including data from TOR, as well as autofill value information including banking and credit card details. In addition, the malware can search for cryptocurrency wallet information, take screenshots and record private messages from various software.
What’s more, Vidar is also known to be able to steal digital coins from offline wallets. In fact, holders of Litecoin, Bitcoin, Ethereum, Zcash, and DashCore are in potential danger, as these are the cryptocurrencies currently supported by the malware.
After collecting all targeted information, the malware archives it and sends the stolen data to a control server, after which Vidar removes traces of its work and deletes itself from the system.
Vidar malware analysis
A video recorded in ANY.RUN malware hunting service allows us to take a closer look at the lifecycle of Vidar.
Figure 1: A visual process graph generated by ANY.RUN
Figure 2: The customizable text report provided by ANY.RUN is a perfect tool to share the results of an analysis
Vidar execution process
After the user downloads and runs a malicious file it spawns a child process and starts to collect information from the infected device. Often, after the information was collected the malware kills and deletes itself through a command line command.
How to avoid infection by Vidar?
When spread via spam email campaigns, Vidar stealer requires the user to download and run a malicious file in order to enter an active state and begin execution. Therefore, following some basic online safety rules can ensure that users will stay safe from this malware.
As such, users should be careful when downloading attachments in emails from unknown senders. The best practice is to avoid downloading such files altogether, therefore not putting oneself in danger at all.
In addition, downloading only licensed software from trustworthy sources and avoiding gaming hacking clients greatly reduced the risk of being infected with malware such as Vidar which uses these attack vectors to infect victims.
The distribution process of Vidar
Like other malware, Vidar / Arkei is distributed through spam email campaigns as a malicious attachment. In addition, cases of Vidar being distributed using shady software and gaming hack clients have also been recorded. Vidar targets users all over the world with the exception of some ex-USSR countries, including Russia.
How to detect Vidar / Arkei using ANY.RUN?
Some malware creates files in which it named itself. You can find such info about Arkei trojan using ANY.RUN's "Static Discovering". Open either "Files" tab in the lower part of the task's window or click on the process and then on the button "More Info" in the appeared window. After that, all you need to do is just click on the file.
Figure 3: Arkei's log file
Conclusion
Vidar / Arkei is a highly dangerous information stealer trojan, distributed as malware as a service. Thanks to its extensive stealer feature set, Vidar trojan can be used to retrieve a wide variety of information, including steal select cryptocurrency coins from the users. Additionally, Vidar is capable of stealing data from TOR.
Thankfully, malware hunting services like ANY.RUN allows researchers to conduct extensive studies of malware samples in a secure environment, allowing to spread information about the danger and develop effective countermeasures.
